Power law damage¶

Overview¶

This object implements a “standard” damage model proportional to a power law in stress and directly to the effective inelastic strain. The damage function is

$w = A \sigma_{eff}^n \sigma_{eff} = \sqrt{\frac{3}{2} \operatorname{dev}\left(\bm{\sigma}\right):\operatorname{dev}\left(\bm{\sigma}\right)}.$

The standard damage model multiplies this function by the inelastic strain rate in computing the damage update.

Parameters¶

Parameter	Object type	Description	Default
`elastic`	`neml::LinearElasticModel`	Elasticity model	No
`A`	`neml::Interpolate`	Prefactor	No
`a`	`neml::Interpolate`	Stress exponent	No

Class description¶

class PowerLawDamage : public neml::StandardScalarDamage ¶

Simple power law damage.

Public Functions

PowerLawDamage(ParameterSet &params)¶: Parameters are an elastic model, the constants A and a, the base material model, the CTE, a solver tolerance, solver maximum number of iterations, and a verbosity flag

virtual void f(const double *const s_np1, double d_np1, double T_np1, double &f) const¶: Damage = A * s_eq**a (times the inelastic strain rate)

virtual void df_ds(const double *const s_np1, double d_np1, double T_np1, double *const df) const¶: Derivative of f wrt stress.

virtual void df_dd(const double *const s_np1, double d_np1, double T_np1, double &df) const¶: Derivative of f wrt damage.

Public Static Functions

static std::string type()¶: String type for the object system.

static ParameterSet parameters()¶: Return the default parameters.

static std::unique_ptr<NEMLObject> initialize(ParameterSet &params)¶: Initialize from a parameter set.